Radio tuning mechanism



NOV. 3, 1942. J. E

RADIO TUNING MECHANISM Filed April 9, 1941 2 Sheets-Sheet l 2 w 5/ v a J m 4 4 3 mm: \W w 4 1 J 5 d Q J 2% f 7 )a 4 a 4 a w hmm m 5 Nov. 3, 1942. .1. H. TEAF RADIO TUNING MECHANISM Filed A ril 9, 1941 2 Sheets-Sheet 2 INVENTOR 42; H 75 BY p ATTORNEY button type,

Patented Nov. 3, 1942 UNITED STATES PATENT OFFICE RADIO TUNING MECHANISM John H. Teal, Westmont, N. J assignor to Radio Condenser Company, Camden, N. J.

Application April 9, 1941, Serial No. 387,604

16 Claims.

This invention relates to tuning devices especially adapted for use with radio receiving sets, and particularly to tuning structures of the pushwherein any one of a number of push buttons is pushed inwardly to bring in a desired station for which the parts of a particular slidable member are adjusted.

Various types of mechanical tuning structures have been proposed, both of the pivoted lever type and of the sliding plunger type. In both types of tuners, a positioning member is used which has a pair of engagement surfaces on opposite sides of its longitudinal axis which are engaged by a setting device or cam carried by the tuning arm or plunger. In practically all of these prior art structures a clamping screw is used for the purpose of adjusting the position of the setting device which engages the positioning member that in turn operates the rotor of a condenser or some equivalent tuning part.

In some of these structures the adjusting screws are not readily accessible. In some cases access to the interior of the radio set must be obtained to make the adjustment. In smaller radio sets the screw adjustment is sometimes brought to the outside as a part of the slide mechanism. One objection to the screw adjustment is that varying degrees of screw tightness will give uncertain strength of clamping or fastening of the setting device, as a result of which the setting device is apt to be forced out of its adjustedv position through use of the instrument.

It is the object of my present improvement to entirely eliminate the useof screwsv for adjusting the setting device of the various plunger or slidable structures.

Another object of my invention is to provide an improved construction in which the setting of any one plunger may be quickly and easily accomplished without the use of any tools.

Another object -of my invention is to provide an improved construction which will cause the least possible shifting of the setting device while it is being locked in its adjusted position.

A still further object of my invention is to provide a slidable tuner which is cheap to manufacture, yet one which will be positive in its actions during operations.

These and other objects will appear to one skilled in the art of constructing tuners, from a reading of the following specification taken in connection with the annexed drawings, wherein: r

Figure 1 is a side elevation of a slidable structure or unit for tuning in a station, two of the members being shown in the position preliminary to adjusting the setting device which engages the positioning member of the tuning structure.

Figure 2 is a view looking at the'bottom of Figure 1.

Figure 3 is a side elevation of a modified form of construction, the operating button being shown in section,

Figure 4 is a longitudinal, sectional view through Figure 3, some of the parts being shown in elevation.

Figure 5 is a side elevation of a still further modified form of construction, with the slide and actuator members in released position,

Figure 6 is a part-sectional and part-plan view looking down on the top of Figure 5, with the slide and actuator parts in locking position.

Figure 7 is a view on the line of Figure 5.

In Figure 1, I have shown a slidable structure which is composed of a slide member I operatively connected to an actuator part 2 in a manner to be presently described. The slide I has a portion 3 which is adapted to be supported in a frame carrying the various push-button units, and in many cases, the tuning means such as a condenser. The forward part of the slide member I has portions 4 and 5 which slide in the front frame member of the structure. The slide I has a lug 6 to which a return spring may be attached, the other end of the spring being connected to the frame member in the usual manner. Riveted t the slide I, as by rivets l is a bracket 8.

Between the bracket 8 and the member I there is positioned a thin strip 9 of friction material, such as emery or fine sandpaper, which extends under the setting device [5 and is held in place by the pivot pin l6. While it is not absolutely necessary to use this element, it does have the advantage of increasing the frictional engagement between the setting device and the slide I, whereby the setting device is securely locked to the slide in a manner to be hereinafter described. Between the bracket 8 and the heads of the rivets 1, there is positioned a spring I0 which extends through an opening in theupturned portion H. The free end l2 of the spring I0 terminates a short distance back of projections 13 which are formed downwardly from the inner end of a lever M, the inner end of which passes through the same opening in the upturned portion ll of of thespring l tilts the lever upwardly so that the projections |3 are free from the surface of the setting device is which is pivoted by a pin IE to the slide Theslide I is provided with a T-shaped slot H to receive a T-shaped lug l8 formed inwardly from the endof a projection l9 formed from the material of the actuator 2, so that when these parts are assembled, through the mediznn of the T-shaped slot H, the member I and he T-shaped lug on the actuator are held in operative position. To reduce the sidewise play between the actuator 2 and the slide a lug 20 this construction quite a strong push isrequired on the button 26 to cause the lever end 24 to 25 ride up onto the projection H], which will. then.

about its fulcrum point in the projecting end ll of the bracket 8, and forcing the projections it into gripping engagement with the setting device l5. If desired, stiffening ribs 21 may be formed in the slide I.

With the slide i and the actuator 2 in the position shown in Figures 1 and 2, the setting device or cam i5 is free to swing about its pivot It, so that its two engagement points 28 and 2 9 will engage a positioning member 3|]. that is rotatably connected between the end plates or other parts of" the frame structure carrying the pushbe engaged by the fiat portion 25, tilting the lever K button tuners; and when a condenser is mounted in the same frame, the positioning member 30 is connected in any suitable manner with the rotor of the condenser. Since these latter details and their method of operation are old and well known, they are not shown in the drawings.

In Figures 3 and 4 the slide 3| is somewhat differently constructed than theslide i in Figures 1 and 2. However, it does have a part 32 which is the same as the end 3 of the slide i. The setting device 33 is also differently shaped from the setting device i5 and is secured in any adjusted position in a difierent way, as by a gripping pin 35 securely fastened to the inner end of a slidable lever 34. The pin 35 has an enlarged head 36 adapted to be passed through a hole 37, after which the pin is pushed back in a slot extension of the hole 3? to the position shown in Figure 4, being held in the slot bythe enlarged head 35.

The outer end of the slidable lever M has an upturned end 42 which is formed by a suitable tool into four. displaced portions; two of which, 43, are substantially identical and formed away from the axial center of the lever, and two por-' tions 44 formed in the opposite direction. These offset portions are threaded to receive a screw 45 which carries aball or is formed with a ball formation 46 thereon. A lever 41 is pivoted at 48 to the slide 3|. A seat 49 is formed in the a stud 52 on the projection50. The slidable lever 34 also has a positioning stud 53 to locate the 7 other end of the spring 5|.

. that this is not necessary.

,The outerend of the slide 3| has oppositely disposed shoulders 54, formed by the reduced width at this end of the slide, to receive a pushbutton 55. The push-button 55 may be made of any satisfactory material, but preferably has at least two oppositely disposed liners 56 and 51 of metal, having grooves to receive the end of the slide 3|. The metal strip or portion 51 is provided with a cam surface 58, extending intoa ramp 59, which is adapted to be initially engaged by the curved surface 60 at the end of the lever, so that when the button 55 is pushed into position as shown in Figure 3, the outer end of the slidable lever 34 is forced upwardly against the end of the lever 41 through the ball joint connection heretofore described and against the tension of the spring 5| which may be adjusted by the screw 45.

The counterclockwise movement of the outer end of the member 34 on the bearing of its pin 35, and the lever 47 with the ball 46, causes the slidable lever 34 to slide or move forwardly a slight distance against the tension'of the spring 5|, thereby causing the portion 38 of the pin 35 to engage the inner peripheral surface39 of the setting device 33, and forcing it against the arcuately formed seat 40 in the stop or seat plate 4| fastened to the slide 3|. If desired, this gripping effect may be enhanced by making the portion 38 somewhat eccentric, but I have found To make an adjustment of the setting device 33, the push-button 55 is pulled from the slide 3|, allowing the spring 5| and the lever 41 to move the outer end of the lever 34 downwardly, thereby releasing-the setting device 33 so that the positioning member 30, which is moved by the tuning button or dial of the set, will move the. setting device 33 to the location determined by the positioning member 30, it being understood that the slide 3| is held pushed forwardly into tuning position. While the setting device 33 is held in the adjustedTposition, the push-button 55 is pushed over the end of the slide, thereby locking the setting device 33 in its adjusted position.

In Figures 5 and 6, the slide 3| is substantially the same as the slide shown in Patent 2,230,852, I

issued February 4,1941, to myself and Albert G. Shafer; that is to say, it has an end 62 servin as an inboard bearing on a frame member, and an arcuately formed seat 63 for a corresponding surface on a setting device 54 which is held in position by a backing member 65 fastened to the slide in any satisfactory manner as by rivets 66 and 6? which also serve to anchor a resilient member Bhto the slide. The spring 68 has an end 69 which passes in front ofthe setting member E i for engagement with the inner sides of the projections "i0 and N that contact with the positioning member 30 to limit the rotation of the member 64 Thus the spring 68 serves to prevent the setting devices 64 from falling out of its seat -when it is left free to move during the time of actuator member 12 having a slot 13 therein g to receive the stem of the rivet 14, the head 15 of which is enlarged to span the slot 13, whereby the rivet I4 acts as a; guide arid support for the outer end of the actuator 12. The actuator 12 has a fold or cam surface 16 formed therein, with a pair of spaced upturned lugs '11 and 18 which act as guide members for a lever 19 that is pivotal-1y mounted at in a slot in the bracket projections 84 formed therein similar to the projections I3 shown in Figure 1 for engagement withthe surface of the setting device 64 when the actuator member 12 is pushed into the position shown in Figure 6, whereby the setting member-which is pushed backwardly against the arcuately formed edge seat in the slide by the positioning device 38-is laterally forced against the backing member 65. r If desired, a strip 89 of friction material may be used between the backing member and the slide member so as to get a better frictional engagement between one side of the setting member and the backing member. pressure substantially at right angles to the plane of the setting device, as in the form shown in Figures 1, 2, Sand 6, reduces to a minimum any chance of causing the setting device to shift from its adjusted position.

It may be mentioned that side wobble of the inner end of the actuator 12 is prevented by cutting out a portion 85, leaving two fingers 86 and 81 which slide in notches cut in the sides of the bracket 8| as more clearly indicated in Figure 7;

In this form of slidable tuner the push-button has been omitted as it is to be understood that any suitable. type of button may be attached to the outer end of the actuator 12. The slide BI is provided with a hole 88 for one end of a return spring, whereby the slidable structure is returned to normal position 'after the pushing force has been removed from the operating button. The operation of this slide, so far as adjusting the setting member is concerned, and operating the slide for tuning purposes, is the same as the form shown in Figures 1 and 2, except that itmay be mentioned that when the actuator 12 is pulled outwardly to release the setting device for adjustment purposes, the end 68 of the spring 68 moves the lever 18 so that the projections 84 thereon are free from clamping engagement with the setting device 84.

It will be obvious that certain of the details entering into the construction of these devices Applying a clamping Y the spring 68- and it also has a pair of spaced end fully overlying a, substantial of the setting device, while the other'end of the lever is adapted to engage said raised portion on the actuator to move the lever to lockingly en gage the setting device during a. pushing operation on the actuator and to release the setting device for adjustment on .a pulling operation on the actuator, and means on the outer end of the actuator for manipulating it.

3. A slidable tuning structure as set forth in claim 2, further defined in that the slide and actuator member are interlocked by a T-shaped slot in one memberand a T-shaped lug on the other member, the actuator having a pair of oppositely positioned guide rims, one of which hasa slot therein to receive a guide lug on the slide member.

4. A slidable tuning structure as set forth in. claim 2, further defined in that the said lever has a plurality of projections having fiat faces for engaging a face of the setting device.

5. A slidable tuning structure as set forth in claim 2, further defined in that the said lever has aplurality of projections having flat faces for engaging a face of the setting device, with means disposed between the surface of the slide member and one face of the setting device for increasing the coefficient of friction between these surfaces.

6. A slidable tuning structure as set forth in claim 2, further defined in that the said lever has a plurality of projections having flat faces for engaging a face of the setting device, and a thin flat spring fastened to the slide member and terminating adjacent said lever projections and in engagement with the lever end to move this end of the lever when it is released out of any substantial contact with the setting device.

7. A slidable tuning structure as set forth in claim 2, further defined in that a bracket is clamped to the slide, the bracket having a seat therein to receive the said lever, a thin fiat spring being clamped alo with the bracket and engaging the end of th lever to hold it in position in the bracket slot when the lever is in its unclamping position.

8. A slidable tuning structure as setforth in claim 2, further defined in that the slide has a backing member fastened thereto and the slide may be varied without departing from the spirit I of my invention and the scope of the appended claims.

What I claim is: 1. In a tuning structure for a radio set, a positioning member for actuating a tuning element,

" a push-button slidable-structure carrying an adjustable setting device for directly engaging said positioning member, the said structure havlug two parts slidably interconnected, a raised portion on one part and a lever connected with the other part and extending over' said raised portion and forced by said portion into locking engagement with the setting device.

2. A push-button slidable tuning structure for use in a radio set including, support means, a slide member carried by the support means, an actuator member slidably but non-rotatably, pushably and pullably carried directly on the slide member, the actuator member having a raised portion thereon, an elongated lever extending lengthwise of the slide member and pivoted near one end on the slide member and having this member has an arcuate edge surface to receive a corresponding edge surface on the setting device, and a spring fastened to the backing member and having an end passing closely in front of the setting device to hold it in operative position while being adjusted, the extremity of the spring end engaging a seat in the clamping end of the lever.

.9. A slidable tuning structure as set forth in claim 2, further defined in that the slide has a backing member fastened thereto and the slide member has an. arcuate edge surface to receive a corresponding edge surface on the setting device, and a spring fastened to the backing member and having an end passing closely in front of the setting device to hold it in operative position while being adjusted, the extremity of the spring end engaging a seat in the clamping end of the of the setting device to cause the opposite face to frictionally engage the backing member.

10. A push-button slidable tuning structure for use in a radio set including a slide member, a

amount and I adapted to engage entirely laterally a side-face lever pivoted on the slide, a plate having an arcuate seat, a setting device also having an arcuate seat to fit the seat on said plate. the said lever. having means to engage the Setting device, a second lever pivoted on the slide and having one end fiexibly and adjustably connected to the outer end of-the first'lever, the other end of the second lever having a spring connection with the first lever in a manner tending to move the first lever into a position to cause said means to disengage the setting device, and push means to :go over the outer end of the slide, the interior of said push means having a formation to engage the outer end of the first lever to move it to lock the setting device in any adjusted position.

11. A slidable tuning structure as set forth in claim 10, further defined in that said first leverengaging means comprises aportion on the leverpivoting pin which is fastened to the lever.

12. A slidable tuning structure as set forth mzb claim 10, further defined in that the/flexible and adjustable connection between the two levers grooves for the outer end of the slide member and a cam surface for engaging a cam'suriace on v the end of the first lever to move it into locking against the spring and second lever, cup-shaped member is pushed over the positionv when the end of the slide membe.

14 A slldable timing structure as set forth a claim 10, further defined in that the locking pressure between said levers is obtained by a togglelil re action as the pivotal axes of the levers and the said flexible connection approach a straight line through them.

15. In a-tuning device for a radio set, a tuning slide structure having a main slide member and comprises an adjusting screw carried in the free end of the first lever, the screw and end of the second lever having cooperative ball and socket formations.

13. A slidable tuning structure .as set forth in claim 10, further defined in that said push means comprise a cup-shaped member having interior carrying an adjustable settingdevice pivotally mounted on one side of the main slide member, said structure carrying a lever arranged to apply pressure to clamp said settingdevice against said main slide member, slidable means carried on said slide structure to operate said lever to release or clamp th setting device, and a spring arranged to free the setting device when the lever is in. releasing position.

16. A slidable tuning structure as set forth in claim 15, further defined-in that said slidable means when moved in one direction applies the clamping action and when moved in the opposite direction releases the clamping action.

. JOHN H. TEAF. 

